In the practice of many industrial processes, it is desirable to compact compressible cellulosic material in a high consistency mixture during acting on the material to produce a desired end product. For example in the production of artificial fireplace logs, it is desirable to compress the wax and fibrous waste material (e.g. sawdust) prior to extruding the mass of material into logs. In the production of bricks or blocks from mud and straw, the feeding of wood chips to a refiner for the production of wood pulp, and in the feeding of high consistency pulp to high pressure treatment vessels to produce treated wood pulp, etc., compression is desirable. During compression it is not necessarily desirable to change the solids consistency of the slurry.
There is an existing commercially successful device manufactured under license of U.S. Pat. No. 4,534,868 known as the Kamyr RING.RTM. press, manufactured by Kamyr, Inc. of Glens Falls, N.Y. The Kamyr RING.RTM. press includes a housing with an outer solid wall, an arcuate channel having a root wall, and a rotor for rotating the root wall about a horizontal axis. The purpose of this device is to remove liquid from a mass, walls defining the channel being perforated and liquid being extracted from the fibrous suspension through the channel walls during treatment to effect dewatering.
It has been recognized, according to the present invention, that a structure such as a modified form of the Kamyr RING.RTM. press is eminently suited for the compaction of compressible material in order to form a plug of material which is discharged from the housing. The device can be utilized for a wide variety of different industrial processes where compression is desirable. For example it can be utilized to produce a plug of wax and waste fibrous material (such as sawdust) that is fed to an extruder for making processed fireplace logs. It can also be used to compress a mixture of mud and straw into a plug that is fed to an extruder for making bricks or blocks, or for compacting wood chips before they are fed to a refiner, or for compressing high consistency cellulosic fibrous material pulp before it is fed to a high pressure treatment vessel. The plug that is formed prevents passage of vapor back through the plug, and/or forms the material being compressed into a more desirable physical configuration for easy and effective handling, and the production of an end product with a minimum of effort.
According to one aspect of the present invention there is provided a device for compacting compressible cellulosic material in a mixture. The device comprises: (a) A housing having an outer, essentially solid, wall; including a restricting adjustable portion. (b) Means defining a channel having a root wall and a pair of side walls with an open face opposite the root wall, the channel being positioned so that the open face thereof is adjacent the housing outer wall, and all of the walls defining the channel being solid so that liquid may not pass therethrough. (c) Means for moving the root wall, and at least one of the side walls, with respect to the outer wall in the dimension of elongation of the channel. (d) Means for feeding cellulosic mixture to be compressed into the channel at an inlet portion of the housing. (e) An outlet for passage of compressed cellulosic mixture out of the channel and the housing adjacent the restricting adjustable portion of the housing outer wall; and, (f) means for applying force to the restricting adjustable portion so as to control the amount of compaction of the cellulosic mixture being compressed. Preferably, the housing wall is arcuate and the root wall is an arcuate wall of a rotor, the sidewalls extending radially outwardly therefrom, the means (c) comprises means for rotating the root wall and rotor about a generally horizontal axis, and the means (f) comprises a mechanical actuator such as pneumatic cylinder.
A device according to the invention has many uses. For example the inlet thereto may be connected to a source of wax and fibrous waste material, and the outlet therefrom connected to the inlet to an artificial log extruder. Alternatively the inlet may be connected to a source of mud and straw and the outlet to a brick or block extruder; the inlet connected to a source of wood chips and the outlet connected to the inlet to a refiner for refining wood chips into pulp; or the inlet connected to a source of high consistency cellulosic fibrous material pulp and the outlet connected to a high pressure treatment vessel, etc.
In practicing the method according to the invention, the mixture of material to be compressed is introduced into the channel while the root wall is rotated about a horizontal axis. The mixture of material, without substantial liquid removal, is compressed so that a plug of compacted material forms. The plug is then discharged from the channel to whatever device it is connected to; e.g. a high pressure pulp treatment vessel where cellulosic fibrous material having a consistency of about 16% or more is being treated; a refiner where wood chips are being acted upon to be formed into wood pulp; an extruder for bricks or blocks where mud and straw are being acted upon to form bricks or blocks; or an extruder for making artificial logs where waxes and fibrous waste materials are being acted upon to produce logs for burning in fireplaces.
It is the primary object of the present invention to provide a device and method for the effective compaction of compressible material during industrial processes. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.